The purpose of this arm-crank ergometry (ACE) study was to provide a greater understanding of the influence to which specific cervical and thoracic spinal cord injuries contribute to reduction in optimal cardio-respiratory and metabolic function. Twenty five male volunteers aged 20 to 47 years participated. Twenty disabled wheelchair-confined spinal cord injured (SCI) subjects were equally divided into four ‘site-specific’ groups based on the lesion being within either high- or low- cervical or thoracic anatomical regions. Five physically non-disabled controls (As) were included. Measured variables tended to decrease progressively from As to high-level quadriplegics. Analysis revealed a high variance in maximum cardio-respiratory performance levels between groups (P < 0.001). These findings confirm that limitation to upper body physical capabilities in the SCI during high-intensity ACE is dependent on specific lesion site. Considerable variability in performance levels were measured in those suffering lesions within closely approximating anatomical regions. Results also suggest a greater importance in the location of cervical rather than thoracic injuries in contributing towards higher relative losses in maximal cardio-respiratory and metabolic potential. Alterations in body composition and varying severity of muscle paralysis likely also play a contributing role in reducing optimal metabolic function in SCI individuals. The importance for stringent classification techniques of spinal cord lesion site in predicting upper body physical exercise potential in the SCI has therefore been highlighted in this study.
With civilized environments in modern society, since the people tend to depend more on artificial illumination than on natural illumination which makes less discrepancy between day and night life, clarifying the relationship between human life and illumination is necessary. In our previous studies, we found that the subjects dressed faster with thicker clothing in the morning than in the evening when the room temperature decreased from 30°C to 15°C over 1 hour. We considered these results in terms of load error between the actual and set-point values in the core temperature. The present study was designed to examine the effect of bright light (3, 000 lx) / dim light (50 lx) exposure (09:30 h-14:30 h) on dressing behavior and thermoregulatory responses in the elderly people during the afternoon cold exposure. Five female subjects were instructed to dress to feel comfortable when the room temperature was decreased from 30°C to 15°C (15:00 h-17:00 h). The subjects felt cooler and dressed more quickly with thicker clothing after dim light exposure, it is conceivable that the set-point value of core temperature is reduced under the bright light condition. We discussed these results in terms of the establishment of set-point values in the core temperature at bright light condition. If the set-point of the core temperature is lower in the bright than in the dim light condition in present experiment, the dressing behavior with thinner clothing in the bright light condition is advantageous, since it enables the core temperature to reach its set-point value more easily.
The effects of daily bathing and hot footbath (immersion of feet in hot water) in winter on the sleep behavior of nine healthy female volunteers were studied. Subjects were assigned to three sleep conditions: sleep after bathing (Condition B), sleep after hot footbath (Condition F), and sleep without either treatment (Control). Polysomnograms (consisting of electro-encephalograph, electrooculograph, and electromyograph) were obtained, and body movements during sleep were measured while monitoring both the rectal and skin temperatures of subjects. In addition, subjective sleep sensations were obtained with a questionnaire answered immediately by the subjects on awakening. The rectal temperature increased by approximately 1.0°C under Condition B, but this elevation was not observed under Condition F compared with Control. In contrast, the respective increases in the mean skin temperature of participants subjected to bathing and hot footbath were greater than those of Control, although these temperature differences became negligible 2 h after subjects went to bed. The sleep onset latency was shortened under both conditions compared with Control. Body movements during the first 30 min of sleep in Control were greater than under the other conditions. Rapid eye movement (REM) sleep decreased under Condition B compared with Condition F, and stage 3 was greater under the latter condition compared with Control. As such, the subjective sleep sensations were better under the two treatment conditions. These results suggest that both daily bathing and hot footbath before sleeping facilitates earlier sleep onset. A hot footbath is especially recommendable for the handicapped, elderly, and disabled, who are unable to enjoy regular baths easily and safely.
A model for foot skin temperature prediction was evaluated on the basis of 2 experiments on subjects at various environmental temperatures (light seated manual work at -10.7°C (Study 1), and a short walking period in combination with standing and sitting at +2.8°C, -11.8°C and -24.6°C (Study 2), with boots of 3 insulation levels. Insulation of the footwear was measured on a thermal foot model. Predicted and measured data showed a relatively good correlation (r=0.87) at the 2 colder conditions in Study 2. The environmental temperature of 2.8°C was not low enough at the chosen activity for a considerable foot skin temperature drop. In Study 1 the predicted temperature stayed higher for the whole exposure period and the difference between the predicted and the measured foot skin temperatures grew proportionally with time, while subsequent warm-up curves at room temperature were almost parallel. In Study 1 the correlation was 0.95. However, the paired t-test showed usually significant differences between measured and predicted foot skin temperatures. The insulation values from thermal foot measurements can be used in the model calculations. Lotens’ foot model is lacking activity as direct input parameter, however, the blood flow is used instead (effect through Tcore). The Lotens foot model can give reasonable foot skin temperature values if the model limitations are considered. Due to the lack of activity level input, it will be difficult to make any good estimation of foot skin temperature during intermittent exercise. The rate of the foot temperature recovery after cold exposure was somewhat overestimated in the model - the warm-up of the feet of the subjects started later and was slower in the beginning of the warm-up than in the prediction. It could be useful to develop the model further by taking into consideration various wetness and activity levels.
The purpose of this study was to investigate EEG changes in subjects directly after inhalation of essential oils, and subsequently, to observe any effect on subjective evaluations. EEG and sensory evaluation were assessed in 13 healthy female subjects in four odor conditions. Four odor conditions (including lavender, chamomile, sandalwood and eugenol) were applied respectively for each subject in the experiment. The results were as follows. 1) Four basic factors were extracted from 22 adjective pairs by factor analysis of the sensory evaluation. The first factor was “comfortable feeling”, the second “cheerful feeling”, the third “natural feeling” and the fourth “feminine feeling”. In the score of the first factor (comfortable feeling), the odors in order of high contribution are lavender, eugenol, chamomile and sandalwood. 2) Alpha 1 (8-10 Hz) of EEG at parietal and posterior temporal regions significantly decreased soon after the onset of inhalation of lavender oil (p<0.01). Significant changes of alpha 1 were also observed after inhalation of eugenol or chamomile. The change after inhalation of sandalwood was not significant. These results showed that alpha 1 activity significantly decreased under odor conditions in which subjects felt comfortable, and showed no significant change under odor conditions in which subjects felt uncomfortable. These results suggest a possible correlation between alpha 1 activity and subjective evaluation.
Although numerical models on the shoulder complex joint are currently available, many are impractical because of the procedural complexity coupled with limited and mere simple simulations. The present study defined the clavicle-scapula system as the “base of the humerus” in determining the position of proximal head of humerus, rendering conclusive innovation of a six degree of freedom (DOF) shoulder complex joint model. Furthermore, a complete measurement system where evaluation by calibrating the actual values via the use of an electromagnetic tracking device (ETD) was developed based on the innovated model. The special calibration method using optimizing calculation to work out the rotational center of humerus was employed and actually tested if the theoretical consideration was practically available. As a result of accuracy check experiments, the measurement error was defined within 2-3 mm, indicating sufficient accuracy in studies for human movement. Our findings strongly advocate that the benefit of this novel measurement system would contribute to studies related to shoulder movements in physiological anthropology.
The objective of this study was to confirm the effects of ADL (Activity of Daily Living) and gender on circadian rhythms of the elderly in a nursing home. Twenty-one elderly volunteers, aged over 65 years, were divided in four groups depending on their ADL and gender: subjects with almost no problem in ADL (H males, H females) and those who were almost bedridden (L males, L females). Oral temperature, heart rate, blood pressure, time of sleep and wake, subjective sleepiness, overall feeling and vitality were measured every 4 hours during the day continuously for six days. The circadian rhythm was calculated by using the least squares fit of cosine function. Subjective sleep quality was also surveyed. In the sleep/wake rhythm, the mesor was significantly higher in L males compared to the other groups and the amplitude was significantly lower in L females compared to other groups. The subjective sleepiness was higher in L males compared to the other groups and L females showed a higher sleepiness compared to H females. No significant difference among the group was observed in subjective sleep quality. In conclusion, these results indicate that the subjective sleepiness and sleep/wake rhythm differ depending on ADL and gender, although no significant difference was observed in physiological parameters. ADL and gender based difference in subjective sleepiness and sleep/wake rhythm should be taken into account with regard to the care of the elderly in nursing homes.